US5206575A - Device for controlling an AC motor - Google Patents

Device for controlling an AC motor Download PDF

Info

Publication number
US5206575A
US5206575A US07/610,248 US61024890A US5206575A US 5206575 A US5206575 A US 5206575A US 61024890 A US61024890 A US 61024890A US 5206575 A US5206575 A US 5206575A
Authority
US
United States
Prior art keywords
current
signal
control
power
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US07/610,248
Other languages
English (en)
Inventor
Yoshinobu Nakamura
Hiroshi Mochikawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Assigned to KABUSHIKI KAISHA TOSHIBA, A CORP OF JAPAN reassignment KABUSHIKI KAISHA TOSHIBA, A CORP OF JAPAN ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: MOCHIKAWA, HIROSHI, NAKAMURA, YOSHINOBU
Application granted granted Critical
Publication of US5206575A publication Critical patent/US5206575A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/04—Arrangements for controlling or regulating the speed or torque of more than one motor
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
    • H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
    • H02P23/26—Power factor control [PFC]
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/28—Arrangements for controlling current

Definitions

  • This invention relates to a control device for an AC motor using an inverter circuit.
  • Control devices for AC motors may be of many different types, depending on the type of the AC motor to be controlled.
  • This invention is concerned with a device for controlling induction motors and brushless motors equipped with a rotor of the permanent magnet type.
  • the numeral 1 denotes a DC current source.
  • the numeral 2 denotes an inverter circuit for passing current to stator windings 3U, 3V and 3W of brushless motor 3.
  • Numerals 4, 5 and 6 denote filter circuits that shift by 90 degrees the phase of terminal voltages UV, VV, and WV containing the induced voltages generated in stator windings 3U, 3V and 3W.
  • Numeral 7 denotes a detection circuit whereby the neutral point voltage NV is obtained from the output signals of these filter circuits 4 to 6.
  • Numerals 8, 9 and 10 are comparators that respectively compare the output signals of filter circuits 4 to 6, which constitute first order delay elements, and neutral point voltage NV.
  • Numeral 11 denotes a control circuit.
  • FIG. 23 is a timing chart showing the operation of the prior art example.
  • the terminal voltage UV (see FIG. 23(a) generated in stator winding 3U contains a voltage spike that is produced by conduction of the opposite arm return flow diode.
  • the terminal voltage UV is shifted in phase by 90 degrees by means of filter circuit 4, producing the phase-shifted voltage DUV as shown in FIG. 23(b).
  • this phase-shifted voltage DUV and the neutral point voltage NV shown in FIG. 23(b) are compared by comparator 8, to obtain a phase detection signal PSU as shown in FIG. (23c).
  • position detection signals PSV and PSW being obtained as shown in FIG. 23(d) and (e) from comparators 9 and 10, based on terminal voltages VV and WV.
  • These position detection signals PSU, PSV and PSW are signals that are 120 degrees different in phase for 180 degrees conduction.
  • this control circuit 11 is made to output six commutation signals, which are applied to the bases of the transistors that constitute the switching elements of inverter circuit 2.
  • the size of the voltage spike component contained in terminal voltages UV, VV and WV varies depending on the magnitude of the current, i.e., the load of stator windings 3U, 3V and 3W, so if the load fluctuation is large, a phase error is produced in the signal waveform of filter circuits 4 to 6 et seq, causing a stability problem.
  • a voltage type PWM inverter 12 consists of a rectifier circuit 14 that rectifies the three-phase AC voltage of three-phase AC power source 13, a smoothing capacitor 15 that smooths this rectified voltage, and a main inverter circuit 16 to which this smoothed DC voltage is applied.
  • the AC output voltage from main inverter circuit 16 is then applied to three-phase induction motor 17.
  • the current Idc flowing in the DC bus of inverter 12 is detected by current detector 18 and supplied as detection current I to low pass filter (LPF) 19.
  • LPF 19 extracts the fundamental wave of the detected current I and outputs it as frequency correction value ⁇ f.
  • PWM pulse width modulation
  • This pulse width modulation control circuit 21 is supplied with a voltage command value V* obtained by converting the frequency command value f* by means of a frequency-voltage (f-V) conversion circuit 22.
  • pulse width modulation control circuit 21 performs pulse width modulation control by applying a base signal to the power transistors of main inverter circuit 16, based on reference frequency value f and voltage command value V*.
  • the mean value of the current flowing in the DC bus of inverter 12 is proportional to the power supplied to three-phase induction motor 17.
  • torque fluctuation is proportional to power fluctuation controlling the mean current of the DC bus of inverter 12
  • torque control of three-phase induction motor 17 can be performed, and production of vibration can be prevented.
  • the above control device is effective when the speed of revolution of the three phase induction motor 17 is sufficiently high, and the ratio of variation of speed of revolution is very small, during low speed operation, when the speed of revolution is low, the amount of power change for a given change of torque falls off. Even if this is therefore compensated by dividing by the speed of revolution or by the inferred value of the speed of revolution so as to remove dependence on the speed of operation, the lowered S/N ratio means that sufficient accuracy is not obtained. Stable driving of the inverter during low speed operation is therefore difficult.
  • This invention was made after consideration of the above circumstances. Its first object is to provide a control device for an AC motor providing good response characteristics and improved stability during sudden accelerations or decelerations and load fluctuations, by controlling the AC motor in accordance with the amount of change of current. Its second object is to provide a control device for an AC motor whereby the AC motor can be driven in a stable manner even during low speed operation.
  • a specific construction in order to achieve these objects is equipped with: current detection means that detects a prescribed amount of change of current of the inverter circuit; first calculating means that calculates the power factor or power from the detection signal of this current detection means; a second calculation means that calculates the control amount of the AC motor from the output signal of this first calculation means; and an inverter control means that controls the inverter circuit on the basis of this second calculation means.
  • the current on the DC side or AC side of the inverter circuit is detected; the power or power factor is calculated from this detected current value; the control amount of the AC motor is calculated from this calculated value; and said inverter circuit is controlled on the basis of this control value.
  • FIG. 1 is a block diagram showing an overall electrical layout of a first embodiment of the present invention.
  • FIG. 2 is a block diagram showing an example layout of a voltage frequency calculation circuit of a first embodiment of the present invention.
  • FIG. 3 is a block diagram showing an example layout of a current detection circuit of the first embodiment of the present invention.
  • FIG. 4 is a waveform diagram of a DC current signal under conditions of different power factors of the first embodiment of the present invention.
  • FIG. 5 is a signal waveform diagram showing the action of a current detection circuit of the first embodiment of the present invention.
  • FIG. 6 is a block diagram showing an example layout of a voltage frequency calculation circuit according to a second embodiment of the invention.
  • FIG. 7 is a block diagram showing an overall electrical layout of a third embodiment of the invention.
  • FIG. 8 is a graph showing load characteristic of a permanent magnet type motor under sudden change of load of the third embodiment of the invention.
  • FIG. 9 to FIG. 11 are views showing action of a current mean value calculation means of load of the third embodiment of the invention.
  • FIG. 12 is a block diagram showing an overall electrical layout of a fourth embodiment of the invention.
  • FIG. 13 is a view showing a relationship between output frequency and compensation amount of the fourth embodiment of the invention.
  • FIG. 14 is a block diagram showing a fifth embodiment of the invention.
  • FIG. 15 is a current waveform diagram given in explanation of an operation the fifth embodiment of the invention.
  • FIG. 16 is a block diagram of an overall electrical layout showing a sixth embodiment of the invention.
  • FIG. 17 is a block diagram showing an overall electrical layout of a seventh embodiment of the invention.
  • FIG. 18 is a block diagram showing an overall electrical layout of the present invention.
  • FIG. 19 is a vector diagram given in explanation of the principles of operation of the present invention.
  • FIG. 20 is a block diagram showing an example layout of a control circuit of an eighth embodiment of the invention.
  • FIG. 21 is a block diagram showing an example layout of the control circuit shown in a ninth embodiment of the invention.
  • FIG. 22 is an electrical layout diagram showing a first prior art example.
  • FIG. 23 is a signal waveform diagram of the various parts given by way of explanation of the operation showing the first prior art example of FIG. 22.
  • FIG. 24 is a block diagram showing a second prior art example.
  • a three-phase AC power source 23 is provided whose three-phase AC voltage is supplied to the AC input terminal of a full wave rectifier circuit 24 consisting of six diodes in a three-phase bridge connection.
  • the DC output voltage of this full wave rectifier circuit 24 is applied to DC buses 27 and 28 through a smoothing capacitor 26 constituting therewith a DC power source 25.
  • Numeral 29 denotes an inverter circuit consisting of six switching elements constituted by transistors connected in three-phase bridge fashion, its input terminal being supplied with the DC voltage between DC buses 27 and 28.
  • a three-phase four-pole brushless motor 30 is provided which is equipped with a permanent magnet type rotor 32 and a stator 31 provided with U, V and W-phase stator windings 31U, 31V and 31W. Stator windings 31U, 31V and 31W are star-connected, and are supplied with the AC output voltages from the output terminals of inverter circuit 20.
  • a current detector 33 includes a Hall CT, which is provided in a DC part of inverter circuit 29 constituted by DC bus 27.
  • a current detection circuit 34 together with current detector 33, forms a current detection means 35.
  • the DC current signal Idc that is detected by current detector 33 is supplied to the input terminal 34a of current detection circuit 34.
  • the output I of this current detection circuit 34 is fed to power factor calculation circuit 36.
  • this power factor calculation circuit 36 is such that, based on the DC current signal Idc, a power factor signal ⁇ Idc and current change amount ⁇ Idc' are output as signals from its output terminals and applied to the input terminals of V/F calculation circuit 37 constituting voltage frequency (V/F) calculation means.
  • V/F calculation circuit 37 calculates a voltage signal V, frequency signal F and pulse signal P ⁇ from the power facto r signal ⁇ Idc, current change amount ⁇ Idc' and a speed command value ⁇ * that is supplied from a setting device, not shown.
  • Voltage signal V and frequency signal F are output from its output terminals and supplied to the input terminals of drive circuit 38.
  • Pulse signal P ⁇ is supplied to input terminal 34d of current detection circuit 34.
  • Drive circuit 38 outputs six drive signals, U, V, W, X, Y, and Z which are PWM-controlled in accordance with the voltage signal V and frequency signal F, from its output terminals, and supplies these to the bases of the six transistors of inverter circuit 29. Rotor 32 of brushless motor 30 is thereby made to rotate at the rotational speed designated by speed command value ⁇ *. Also, these drive signals, U, V, W, X, Y and Z are supplied to the input terminal 34c of current detection circuit 34.
  • V/F calculation circuit 37 An example layout of V/F calculation circuit 37 will now be described with reference to FIG. 2.
  • the speed command value ⁇ * is supplied to each of the input terminals of integrating element 40 and V/F control element 41 through acceleration/deceleration time element 39.
  • Integrating element 40 outputs frequency command signal F* from its output terminal and supplies it to the positive (+) input terminal of subtractor 42.
  • V/F control element 41 outputs a voltage command signal V* from its output terminal and supplies it to one of the positive (+) input terminals of adder 43.
  • Power factor signal ⁇ Idc is supplied to one of the input terminals of power calculation element 44, and the other input terminal of power calculation element 44 is supplied with voltage command signal V* through voltage calculation element 45, so that power calculation element 44 calculates the power value W and outputs it from its output terminal.
  • This calculated power value W is supplied to the other positive (+) input terminal of adder 43 through first control element 46, and through second control element 47 is supplied to one positive (+) input terminal of adder 48.
  • Current change amount ⁇ Idc' is supplied to the other positive (+) input terminal of adder 48 through a third control element 49. The result of the addition performed by this adder 48 is output from its output terminal and supplied to the negative (-) input terminal of a subtractor 42.
  • a current amplification circuit 50 forms, together with current detector 33, a current detection means. Its input terminal 34a is supplied with the above mentioned DC current signal Idc, with the result that amplified DC current signal Idc' is output from its output terminal and supplied to input terminal Ia of a current sampling and hold means including a current sampling and hold circuit 51.
  • a current sampling and hold signal generating means 52 includes a current sampling and hold signal generating circuit, whose input terminals 34c are supplied with drive signals U, V, W, X, Y, and Z, whose input terminal 34d is supplied with a pulse signal P ⁇ , and whose output terminal O outputs a sampling and hold signal SH, which is supplied to input terminal Ib of current sampling and hold circuit 51.
  • current sampling and hold circuit 51 output detection current signals I for each phase from its output terminal 34b.
  • FIG. 4 shows an effect of change of power factor on the waveform of DC signal Idc of current detection means 35, in the case where power factor control by inverter circuit 29 is not carried out.
  • the waveform changes with a period of 1/6 (60 degrees in terms of electric angle) of the output frequency, and its change shows a rise on the right.
  • the power factor is leading, as shown in FIG. 4(c)
  • the waveform changes with the same period, but its change shows a fall on the right.
  • the power factor is approximately 1, as shown in FIG. 4(b), a waveform is obtained showing practically no change.
  • the waveform of DC signal Idc therefore varies in a manner which is repeated at electric angle intervals of 60 degrees.
  • a brushless motor 30 can be operated as shown in FIG. 4(b) such that the power factor is approximately uniform, by detecting the difference (Ib-Ia) of the current Ia at a point A immediately in front of each one of these time points, and the current Ib at a point B immediately after each one of these time points, and effecting control such that this difference is zero, i.e., such that currents Ia and Ib are equal. That is, the same operation can be performed as in the conventional brushless motor system in which the positions of the magnetic poles are detected from the terminal voltages of the stator windings.
  • FIG. 5(a) shows the DC current signal Idc' through the DC amplification circuit 50 corresponding to FIG. 4(a).
  • the waveform is extremely complex, owing to the fact that PWM control is effected by means of inverter circuit 29. It is therefore not easy to detect the change in DC current signal Idc with a period of 1/6 of the output frequency as shown in FIG. 4 from the DC current signal Idc' as shown in FIG. 5(a).
  • Drive circuit 38 supplies PWM-controlled drive signals U, V, W, X, Y, and Z, and V/F calculation circuit 37 supplies a pulse signal P ⁇ (see FIG. 5(c)) that is inverted between low level and high level with a period of 1/6 of the output frequency of inverter circuit 29 to current detection circuit 34, respectively.
  • DC amplification circuit 50 is supplied with the DC current signal Idc from current detector 31, which it amplifies and outputs as DC current signal Idc'.
  • Current sampling and hold signal generating circuit 52 inputs drive signals U, V, W, X, Y, and Z and pulse signal P ⁇ and outputs sampling and hold signal SH as shown in FIG. 5(d).
  • current sampling and hold circuit 51 samples and holds the values of DC current signal Idc' every time the sampling and hold signal SH becomes high level.
  • sampling and hold signal SH is output such that, for example, the first high level period (electric angle 0 degrees to 60 degrees) of pulse signal P ⁇ is synchronized with the drive signal for the U phase, and the next low level period (electric angle 120 degrees to 180 degrees) is synchronized with the drive signal for the W phase, this process being carried out repetitively.
  • the detection current signal I of current sampling and hold circuit 51 is current signal IU, IV and IW for the U, V and W phases, respectively. This detection current signal I is applied to power factor calculation circuit 36.
  • power factor calculation circuit 36 detects the detection current signal I that is applied from current detection means 35 with a fixed sampling period, and calculates a power factor signal ⁇ Idc as the value (Ib-Ia) arrived at by subtracting current Ia from current Ib immediately after each electric angle of 60 degrees, and also calculates the current change ⁇ Idc' during this electric angle of 60 degrees.
  • the power factor signal ⁇ Idc indicates the power factor by positive (+) or negative (-) current values, instead of indicating the power factor itself.
  • V/F calculating circuit 37 when speed command value ⁇ * is applied to acceleration/deceleration time element 39, the output of acceleration/deceleration time element 39 rises with an arbitrary acceleration/deceleration time specified by speed command value ⁇ *. This output is integrated by integrating element 40 and output as frequency command signal F*. The output is then compared with an arbitrary V/F pattern by V/F control element 41 to obtain a voltage command signal V* as output. Voltage command signal V* is multiplied by a suitable coefficient by voltage calculator element 45 and supplied to power calculation element 44 as a voltage value. Power calculation element 44 multiplies the voltage value from voltage calculating element 45 with power factor signal ⁇ Idc and coefficient K and outputs the result as power value W. Power value W is therefore given by:
  • First control element 46 that is supplied with this power W, finds the voltage component value Vdc of power value W by calculation, and carries out proportional integration processing:
  • Adder 43 calculates a voltage signal V as:
  • This second control element is controlled every electric angle of 60 degrees. Furthermore, a third control element 49 is supplied with current change value ⁇ Idc', and performs the multiplication:
  • This third control element 49 is controlled in continuous fashion. After this, the outputs of these control elements 47 and 49 indicated by expressions (6) and (7) are added by adder 48 and then supplied to subtractor 42. Subtractor 42 performs a subtraction:
  • V/F calculation circuit 37 calculates the amount of increase or amount of decrease determined by the feedback amount in response to change of the voltage command signal V* determined by speed command value ⁇ * and the frequency command signal F* and DC current signal Idc. As a result, it delivers a voltage signal V and frequency signal F as output. Operation of brushless motor 30 is thereby controlled through drive circuit 38 and inverter circuit 29, such that the power factor is approximately 1.
  • the current flowing in the DC side of inverter circuit 29 including DC bus 27 is detected by current detection means 35.
  • Power factor calculation circuit 36 calculates power factor signal ⁇ Idc and current change amount ⁇ Idc' from the change in this detected detection current signal I, and V/F calculating circuit 37 calculates a voltage signal V and frequency signal F using the result of this calculation and the speed command value ⁇ *.
  • V/F calculating circuit 37 calculates a voltage signal V and frequency signal F using the result of this calculation and the speed command value ⁇ *.
  • the operation of brushless motor 30 is controlled using this voltage signal V and frequency signal F through drive circuit 38 and inverter circuit 29 such that the power factor is approximately 1.
  • the advantages of this are that, in contrast to the prior art in which the terminal voltages of the stator windings were employed for this purpose, there is no need to use a first order delay element constituted by a filter circuit. The result of this is that good response to abrupt acceleration or deceleration and load fluctuations can be obtained.
  • detected current signal I from current sampling and hold circuit 51 is output by sampling and holding the DC current signal Vdc' of the current detection means 35 that detects the current of the DC side (i.e., DC bus 28) of inverter circuit 29.
  • the sampling and hold signal SH that is used for this purpose is obtained from a pulse signal, inverted with a period of 1/6 (electric angle 60 degrees) of the output frequency and from drive signals U, V, W, X, Y, and Z.
  • the power factor can therefore be detected from the change of the waveform of this detected current signal I. It is therefore possible to control current feedback of brushless motor 30, and only a single current detection means 35 need be provided for this purpose. This facilitates signal processing in comparison with the prior art, with the advantages of lower cost and a reduced requirement for mounting space.
  • DC current signal Idc' of current detection means 35 can serve both for detection and protection from overcurrent and overload, as well as for measurement for output display purposes. It is therefore possible to achieve the different objects of current feedback control, protection against overcurrent and overload, and measurement with a single current detection means 36. This further reduces costs and greatly reduces the amount of mounting space required.
  • the detection current signal I of current sampling and hold circuit 51 is detected as current signals Iu, Iv and Iw for each phase U, V and W.
  • a layout could therefore be adopted to perform for example PWM control of inverter circuit 29, as conventionally, by obtaining a current command signal by detecting the difference between the speed command signal and the detected speed signal of brushless motor 20. PWM control is then carried out in accordance with the magnitude of a deviation current value obtained by calculating the deviation between this current command signal that is thus obtained and currents Iu, Iv and Iw flowing in each phase of the brushless motor 20.
  • the voltage signal V that is output from adder 54 is:
  • the control unit includes: a current detector 33 that detects the current in the DC part of inverter circuit 29; a current detection circuit 34 that amplifies the detected current from this current detector 33 and performs waveform shaping by a sampling and hold action; a power factor calculator circuit 36 that calculates the power factor from the output signal of this current detection 34; a current mean value calculation circuit 60 that calculates the mean value of the output signal from current detection circuit 34; a V/F calculation circuit 61 that calculates the V/F control amount from at least one of the results calculated by power factor calculation circuit 36 and current mean value calculation circuit 60; and a drive circuit 38 that output a control signal to a switching element, for example a transistor (not shown) of inverter circuit 26, based on the control amount generated by this V/F calculation circuit 61.
  • a switching element for example a transistor (not shown) of inverter circuit 26, based on the control amount generated by this V/F calculation circuit 61.
  • the current flowing in the DC link section in which conversion is effected from DC to AC is detected by current detector 33, and the detected value is sent to current detection circuit 34, where waveform shaping is carried out by performing an amplification and sampling and holding action. Since a difference of power factor is produced, in order to effect operation with a power factor of approximately 1, as described above, it is necessary to control the difference (Ib-Ia) of the DC currents to be zero. (In the case of a cage-type induction motor (Ib-Ia) is controlled to be an arbitrary value so as to allow use of an arbitrarily selectable input power factor).
  • Power factor calculation circuit 36 therefore calculates the power factor in terms of a difference of currents, just as in the first and second embodiments described above.
  • current mean value calculation circuit 60 inputs the current signal obtained from current detection circuit 34, finds the mean value of the current and continuously calculates the change of current in said interval of electric angle 60 degrees, thereby generating a control amount which it inputs to the V/F calculation circuit 61 constituting the next stage.
  • the main circuit layout in this embodiment is as follows.
  • a three-phase AC power source 23 is converted to DC by a rectifier circuit 24 and capacitor 16.
  • This DC is converted to AC by an inverter circuit 29 and used to drive motor 30.
  • the layout of this control unit includes: a current detector 33 that detects the current on the DC side of inverter circuit 29; a current detection circuit 34 that performs waveform shaping by an amplification and sampling and hold action, etc., on the detection current from current detector 33; a power factor calculation circuit 36 that calculates the power factor based on the output signal from this current detection circuit 34; a correction circuit 70 that calculates the prescribed control gain from a speed command value ⁇ *; a V/F calculation signal 71 that calculates the V/F control amount from the speed command value ⁇ * and the calculation results of power factor calculation circuit 36 and correction circuit 70; and a drive circuit 38 that outputs a control signal to the transistors (not shown) that are the switching elements of inverter circuit 29, based on the control amount generated by V/F calculation circuit 71.
  • V/F calculation circuit 71 also receives the value obtained from correction circuit 70.
  • Correction circuit 70 also receives the speed command value ⁇ *, which is a means of altering the control gain of V/F calculation circuit 71 in accordance with the speed.
  • V/F calculation circuit 71 performs voltage control and frequency control for example in accordance with the following equations in the same way as in the previous embodiments:
  • V1 output voltage
  • V1* command voltage
  • ⁇ Idc' change of DC current corresponding to power factor
  • V2 integrated value
  • K3 proportional gain constant
  • K4 integrated gain constant
  • Control gains (K3, K4, K5) are constants, but these control gains are made variable by correction circuit 7 as described above.
  • FIG. 13 shows a correction for output frequency of the drive device.
  • the correction amounts can be altered to any desired values in accordance with output frequency.
  • controllability at each frequency can be altered by setting the correction amounts of correction circuit 70 to any desired values, determined in accordance with the electric motor and/or load which are to be controlled.
  • correction amounts were made proportional and inversely proportional to frequency
  • the invention is not restricted to this, and these correction amounts could be set to any desired value.
  • it could be arranged for these values to show hysteresis when the frequency rises or when the frequency drops.
  • Numeral 80 denotes a three-phase AC power source.
  • a full wave rectifier circuit 81 pexforms full wave rectification on the three-phase AC voltage from this three-phase AC power source 80.
  • a smoothing capacitor 82 smooths the rectified voltage from this full wave rectification circuit 81 to produce a DC voltage which is applied between DC buses 83 and 84.
  • Numeral 85 denotes a main inverter circuit, to the input terminals of which is applied the CD voltage between these DC buses 83 and 84. These elements together form a voltage type PWM inverter 86.
  • Main inverter circuit 85 is constituted of a plurality of switching elements e.g.
  • a current detection circuit 88 is comprised a Hall CT as current detection means. This detects the current Idc flowing in DC bus 84 of inverter 86 and outputs a detection current I in response to it.
  • a power factor calculation circuit 89 has the detection current I from current detection circuit 88 supplied to its input terminal and performs a calculation as described below, as a result of which it outputs from its output terminal the tangential component tan ⁇ of the power factor angle ⁇ .
  • a subtractor 90 has the tangential component tan ⁇ from power factor calculation circuit 89 supplied to its negative (-) input terminal, and the tangential component tan ⁇ * of power factor angle command value ⁇ * supplied to its positive (+) input terminal, and, as a result, outputs the difference of these, ⁇ tan ⁇ , from its output terminal.
  • a proportional integral (PI) control circuit 91 has the difference ⁇ tan ⁇ from subtractor 90 supplied to its input terminal, and outputs from its output terminal a voltage correction value ⁇ V.
  • An adder 94 receives at one of its positive (+) input terminals the voltage correction value ⁇ V from proportional integral control circuit 91 and receives at its other positive (+) input terminal the voltage command value V* from frequency-voltage (V/F) conversion circuit 92, as a result of which it outputs voltage command value v from its output terminal.
  • frequency-voltage conversion circuit 92 receives at its input terminal frequency command value F* and outputs from its output terminal a voltage command value V* corresponding to frequency command value F*.
  • Numerical 93 denotes a pulse width modulation (PWM) control circuit. This receives at one of its input terminals the voltage command value V from the adder 94, and receives at its other input terminal frequency command value F*.
  • PWM pulse width modulation
  • Inverter control means 95 includes the adder 90, the proportional integral control circuit 91, the frequency-voltage conversion circuit 92, the pulse width modulation control circuit 93 and the adder 94 described above.
  • frequency command value F* is supplied to pulse width modulation control circuit 93. Also, frequency command value F* is converted to a voltage command value V* by frequency-voltage conversion circuit 92, and this voltage command value V* is supplied through adder 94 as voltage command value V to pulse width modulation control circuit 93. In response, pulse width modulation control circuit 93 outputs a pulse width modulation signal corresponding to voltage command value V (V*) and frequency command value F* as a drive signal and supplies it to the base of power transistor 85a of inverter circuit 85.
  • the current Idc is the current flowing in DC bus 84 when one of the three-phase currents (depending on the switching condition of inverter circuit 85) flowing in three-phase induction motor 87 is selected, it is possible to detect one phase of the current flowing in three phase induction motor 87 by extracting it by sampling this at a specific timing obtained from the output pulse modulation voltage waveform. Also, when current Idc is sampled, a sampled waveform Is as shown in FIG. 15(b) is obtained, assuming that this samples phase is successively switched only during a period of 60 degrees of the voltage phase peak.
  • the timing with which sampling is performed is synchronized with the output pulse width modulation voltage, so, if the power factor is 1, the sampled waveform Is is the waveform obtained by full wave rectification of the three-phase current flowing in three-phase induction motor 87, and is a continuous waveform.
  • the sampled waveform Is as shown in FIG. 15(b), is a waveform which is discontinuous at the time-point of the phase changeover.
  • the current values before and after the time-point of this phase changeover are in close relationship with the power factor, so they can be formalized as follows, assuming that the three-phase current flowing in the three-phase induction motor 87 is a symmetrical sine wave.
  • the tangential component tan ⁇ of the power factor angle calculated by power factor calculation circuit 89 is supplied to subtractor 90, and subtractor 90 performs a subtraction:
  • V* voltage correction value
  • the output voltage of inverter circuit 85 is controlled by power factor calculation circuit 89 in accordance with the detection current I of detection circuit 88, such that the tangential part tan ⁇ of the power factor angle ⁇ is equal to the tangential part tan ⁇ * of the power factor angle command value ⁇ *.
  • power factor control can therefore be achieved based on the current flowing in the three-phase induction motor 87 rather than on the change in power. Inverter 86 can therefore control in a stable manner the drive of three-phase induction motor 87 even in low speed operation.
  • FIG. 16 shows a sixth embodiment of this invention. Parts which are the same as in FIG. 14 are given the same reference numerals, and only the parts which are different will be described hereinbelow.
  • numeral 96 denotes an inverse tangent (tan-1) calculation circuit. This receives at its input terminal the tangential component tan ⁇ from power factor calculation circuit 89. Inverse tangent calculating circuit 96 converts the tangential component tan ⁇ that it receives as input into a power factor angle ⁇ , which it outputs from its output terminal. This power factor angle ⁇ is then supplied to the negative (-) input terminal of subtractor 90.
  • Proportional integral control circuit 91 outputs a voltage correction value ⁇ V such that this difference ⁇ V asymptotically approaches zero.
  • FIG. 17 shows a seventh embodiment of this invention. Parts which are the same as in FIG. 14 are given the same reference numerals, and only those parts which are different are described below.
  • humeral 97 denotes a proportional integral control circuit replacing proportional integral control circuit 91. Its input terminal is supplied with difference ⁇ tan ⁇ from subtractor 90, and the circuit outputs frequency correction value ⁇ F.
  • One input terminal of pulse width modulation control circuit 93 is supplied with frequency command value F, while its other input terminal is directly supplied with voltage command value V* from frequency-voltage conversion circuit 92.
  • pulse width modulation control circuit 93 controls inverter circuit 85 in accordance with voltage command value V* and frequency command value F, such that it outputs a three-phase AC voltage of output voltage and output frequency corresponding to these.
  • Proportional integral control circuit 97 outputs a frequency correction value ⁇ F such that the difference ⁇ tan ⁇ asymptotically approaches zero.
  • the seventh embodiment is particularly effective when the power factor angle ⁇ needs to increase when the output voltage has reached its maximum. It may therefore be used in combination with, for example, the fifth embodiment, in a layout wherein switching is effected such that the fifth embodiment is used below the base speed, and the seventh embodiment is used in the fixed output operating condition at speeds in excess of the base speed.
  • An inverter circuit 100 includes a three-phase bridge connection of six switching elements formed by transistors. This is supplied with the DC voltage of DC power source 101 at its input terminal.
  • a three-phase four-pole brushless motor 102 is equipped with a stator 103 provided with U, V and W phase stator coils 103U, 103V and 103W, and with a permanent magnet type rotor 104.
  • Stator coils 103U, 103V and 103W are connected in a star connection, which is supplied with AC output voltage from the output terminals of inverter circuit 100 through output leads 105, 106 and 107.
  • Numerals 108 and 109 denote current detectors consisting of Hall current transformers.
  • Control circuit 113 uses power signals W1 and W2 and a speed command value ⁇ * that is supplied from a setting device 114 to calculate voltage signal V and phase signal ⁇ . These are in turn used to produce six PWM-controlled drive signals DS that are output from its output terminals and supplied to the bases of the six transistors of inverter circuit 100, causing the rotor 104 of brushless motor 102 to rotate with a speed of rotation designated by speed command value ⁇ *.
  • FIG. 19 is a vector diagram showing the relationship of the phase voltage, phase current and line voltage in each phase.
  • Eu, Ev and Ew are the U, V and W phase voltages
  • Iu, Iv and Iw are the U, V and W phase currents
  • ⁇ is the phase difference between the respective phase voltages Eu, Ev and Ew and the respective phase currents Iu, Iv and Iw.
  • Euw and Evw are the line voltages referred to the W phase voltage Ew.
  • Line voltage Euw has a phase difference (- ⁇ /6) with respect to the phase voltage Eu
  • the line voltage Evw has a phase difference (+ ⁇ /6) with respect to the phase voltage Ev .
  • the power factor can be controlled by controlling the passage of current to stator coils 103U, 103V and 103W such that the power W1 and W2 of the two phases are equal, and brushless motor 102 can thus be driven in the same way as conventionally.
  • Speed command value ⁇ * is applied to the respective input terminals of integrating element 116 and V/F control 117 through speed adjustment time element 115.
  • Integrating element 116 outputs a phase signal ⁇ from its output terminal and supplies this to the input terminal of drive control element 118.
  • V/F control element 117 outputs a voltage command signal V from its output terminal and supplies this to one positive (+) input terminal of an adder 119.
  • Adder 119 outputs a voltage signal V from its output terminal, as described below. This voltage signal V is supplied to an input terminal of drive control element 118, and is also supplied to an input terminal of line voltage calculating element 120.
  • Line voltage calculating element 120 receives at its other input terminal a phase signal ⁇ and uses this phase signal ⁇ and voltage signal V to calculate line voltages Euw and Evw, which it supplies as signals to the input terminals of power calculation circuit 112.
  • Power signals W1 and W2 from power calculation circuit 112 are respectively supplied to the positive (+) input terminal and negative (-) input terminal of subtractor 121, and the output signal from the output terminal of the subtractor 121 is supplied through a PI (proportional/integral) control element 122 to the other positive (+) input terminal of adder 119.
  • control circuit 113 when speed command value ⁇ * is applied to speed adjustment time element 115, the output signal ⁇ * of speed adjustment time element 115 rises for a speed adjustment time that can be specified at will by speed command value ⁇ *. This is then integrated by integrating element 116 and output as phase signal ⁇ . It is also compared with a V/P pattern, which can be chosen at will, by V/F control element 117, and output as voltage command signal V. The voltages to be applied to stator coils 113U and 113W can then be calculated from the phase signal ⁇ that is output from integrating element 116 and the voltage signal V that is output from adder 119 that adds a correction to voltage command signal V.
  • Line voltage calculating element 120 calculates these as line voltages Euw and Evw and applies them as signals to power calculation circuit 112.
  • Power calculation circuit 112 calculates powers W1 and W2 as shown by equations (24) and (25) from the phase current signals Iu and Iv that are supplied from current detection means 111 and these line voltages Euw and Evw. These powers W1 and W2 are then fed back to control circuit 113 as signals and supplied to subtractor 121.
  • Subtractor 121 finds the difference between these power signals W1 and W2 and supplies this difference signal to PI control element 122.
  • PI control element 122 performs PI control such that this difference signal is zero or a predetermined value, its output being supplied to adder 119.
  • Adder 119 outputs a voltage signal v by adding the output signal from PI control element 122 to voltage command signal V.
  • the phase signal ⁇ and voltage signal v which are thus obtained are supplied to drive control element 118.
  • Drive control element 118 uses this phase signal ⁇ and voltage signal v to output drive signals DS which it supplies to the bases of the six transistors of inverter circuit 100, thereby causing the rotor 104 of brushless motor 102 to rotate at a speed corresponding to the speed command value ⁇ *.
  • the currents flowing in the U phase and V phase stator coils 103U and 103V are detected by current detection means 111, and these detected current signals Iu and Iv are used by power calculation circuit 112 to calculate powers W1 and W2.
  • Control circuit 113 then obtains a voltage signal v and phase signal ⁇ by PI control such that the difference of the powers W1 and W2 obtained as a result of this calculation is zero or a prescribed value.
  • This voltage signal v and phase signal ⁇ are then in turn used by inverter circuit 100 to control operation of the brushless motor 102.
  • a first order delay element constituted by a filter circuit. This results in good response to abrupt accelerations or decelerations and load fluctuations, and enables stability to be raised.
  • this embodiment has excellent response to external disturbances, detection is possible in the low speed region, and the range of control can be increased.
  • FIG. 21 shows a ninth embodiment of this invention. Parts which are the same as in FIG. 20 are given the same reference numerals. The difference with respect to FIG. 20 lies in that control circuit 113 is additionally provided with an adder 123 and P control element (or it could be a PI control element) 124. A phase signal ⁇ from integrating element 116 is applied to one of the positive (+) input terminals of adder 123, and difference signal from adder 121 is applied to the other positive (+) input terminal of adder 123 through P control element 124, so that a phase signal ⁇ is output from the output terminal of adder 123.
  • control circuit 113 is additionally provided with an adder 123 and P control element (or it could be a PI control element) 124.
  • a phase signal ⁇ from integrating element 116 is applied to one of the positive (+) input terminals of adder 123, and difference signal from adder 121 is applied to the other positive (+) input terminal of adder 123 through P control element 124, so that a phase
US07/610,248 1989-11-10 1990-11-09 Device for controlling an AC motor Expired - Fee Related US5206575A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP1292839A JPH03155392A (ja) 1989-11-10 1989-11-10 電流検出装置
JP1-292839 1989-11-10

Publications (1)

Publication Number Publication Date
US5206575A true US5206575A (en) 1993-04-27

Family

ID=17787029

Family Applications (1)

Application Number Title Priority Date Filing Date
US07/610,248 Expired - Fee Related US5206575A (en) 1989-11-10 1990-11-09 Device for controlling an AC motor

Country Status (5)

Country Link
US (1) US5206575A (ko)
EP (1) EP0629038B1 (ko)
JP (1) JPH03155392A (ko)
KR (1) KR940006168B1 (ko)
DE (2) DE69031573T2 (ko)

Cited By (42)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5475292A (en) * 1992-07-28 1995-12-12 Fuji Electric Co., Ltd. Apparatus for restarting inverter for driving synchronous motor after momentary interruption
US5670859A (en) * 1995-06-23 1997-09-23 General Resource Corporation Feedback control of an inverter output bridge and motor system
US5686807A (en) * 1992-07-17 1997-11-11 Honda Giken Kogyo Kabushiki Kaisha Torque control system for AC motor
US5724477A (en) * 1995-04-20 1998-03-03 Switched Reluctance Drives, Ltd. Compensation for input voltage variation in an electric motor drive
US5764022A (en) * 1993-12-28 1998-06-09 Sanyo Electric Co., Ltd. Air conditioner and inverter driving circuit therefor
US5808880A (en) * 1996-08-30 1998-09-15 Otis Elevator Company Power factor controller for active converter
US5828192A (en) * 1993-02-02 1998-10-27 Honda Giken Kogyo Kabushiki Kaisha Electric vehicle power feed system
US6366049B1 (en) * 2000-05-10 2002-04-02 Ecostar Electric Drive Systems L.L.C. Motor starter and speed controller system
US6400107B1 (en) * 1999-08-04 2002-06-04 Sharp Kabushiki Kaisha Motor control device capable of driving a synchronous motor with high efficiency and high reliability
US6442979B1 (en) * 1999-05-06 2002-09-03 Emerson Electric Co. Washing machine motor control device and method
EP1280264A2 (en) * 2001-07-27 2003-01-29 Hitachi, Ltd. AC current detecting device for inverter apparatus and AC current detecting method therefor
US6531842B2 (en) 2001-06-25 2003-03-11 Schlumberger Technology Corp. Sine wave variable speed drive
US20040207360A1 (en) * 2003-03-25 2004-10-21 Hideo Matsushiro Inverter controller for driving motor, and air conditioner
US20040217728A1 (en) * 2003-04-03 2004-11-04 Mitsuo Kawaji Inverter controller for driving motor and air conditioner using inverter controller
US20040232876A1 (en) * 2003-03-27 2004-11-25 Hideo Matsushiro Inverter control device for driving a motor and an air conditioner
US6832127B1 (en) * 1998-09-18 2004-12-14 Kabushiki Kaisha Yaskawa Denki Motor controller
EP1528660A1 (en) * 1995-12-28 2005-05-04 Kabushiki Kaisha Toshiba Three-phase bridge rectifier
US20060012259A1 (en) * 2004-07-19 2006-01-19 Raser Technologies, Inc. AC induction motor having multiple poles and increased stator/rotor gap
WO2006017026A1 (en) * 2004-07-07 2006-02-16 Raser Technologies, Inc. Motor controller
US20060038530A1 (en) * 2004-07-07 2006-02-23 Rt Patent Company, Inc. System and method for optimizing motor performance by varying flux
US20060208603A1 (en) * 2005-03-18 2006-09-21 Rt Patent Company, Inc. Rotating electric machine with variable length air gap
US20070007929A1 (en) * 2005-07-07 2007-01-11 Kevin Lee System and method of controlling power to a non-motor load
US20070132331A1 (en) * 2005-12-13 2007-06-14 Rt Patent Company, Inc. DC homopolar motor/generator
US20070132334A1 (en) * 2005-12-14 2007-06-14 Rt Patent Company, Inc. Systems and methods for providing electrical contact with a rotating element of a machine
US20070252551A1 (en) * 2004-02-05 2007-11-01 Dyson Technology Limited Control of Electrical Machines
US20070278983A1 (en) * 2004-02-05 2007-12-06 Dyson Technology Limited Control of Electrical Machines
US20080180056A1 (en) * 2001-09-29 2008-07-31 Toshiyuki Maeda Phase current detection method, inverter control method, motor control method and apparatus for carrying out these methods
US20090085510A1 (en) * 2007-09-28 2009-04-02 Manish Pande Motor Drive Using Flux Adjustment to Control Power Factor
US20090189553A1 (en) * 2008-01-29 2009-07-30 Arnet Beat J Method and system for multiphase current sensing
CN101436773B (zh) * 2007-11-15 2012-10-03 上海华建电力设备股份有限公司 一种电动机再起动的方法
EP2582033A3 (en) * 2011-10-11 2014-04-23 Hamilton Sundstrand Corporation Control for a multi-level active rectifier
US20140232308A1 (en) * 2011-10-04 2014-08-21 Mitsubishi Heavy Industries Automotive Thermal Systems Co., Ltd. Inverter apparatus
US9179504B2 (en) * 2009-08-04 2015-11-03 Panasonic Intellectual Property Management Co., Ltd. Electric power converting apparatus and induction heating apparatus
US20160020720A1 (en) * 2014-07-15 2016-01-21 IPH + Limited Drive control system and drive control method
US20160020716A1 (en) * 2014-07-15 2016-01-21 Nidec Motor Corporation Motor control system and method for input current protection
JP2016134959A (ja) * 2015-01-16 2016-07-25 株式会社デンソー モータ始動装置、モータ始動方法
US20160285396A1 (en) * 2015-03-26 2016-09-29 Kabushiki Kaisha Toyota Jidoshokki Controller and in-vehicle motor-driven compressor
CN106411151A (zh) * 2016-08-29 2017-02-15 施电气科技（上海）有限公司 高效绝缘栅双极igbt结构变频器
US20170366101A1 (en) * 2016-06-17 2017-12-21 Denso Corporation Power conversion apparatus
US20180191287A1 (en) * 2015-08-29 2018-07-05 Abb Schweiz Ag System having electrical machine and controller
US10277143B1 (en) * 2018-02-01 2019-04-30 Lsis Co., Ltd. Inverter supplying power to induction motor for driving hoist
US11394286B2 (en) * 2018-09-28 2022-07-19 Safran Power Usa, Llc Process control using amplitude control loop

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5428283A (en) * 1994-05-26 1995-06-27 Alliedsignal Inc. Power factor control of pulse width modulated inverter supplied permanent magnet motor
JP5124899B2 (ja) * 2001-09-28 2013-01-23 ダイキン工業株式会社 モータ制御方法およびその装置
JP4847060B2 (ja) * 2005-07-15 2011-12-28 日立オートモティブシステムズ株式会社 交流モータ駆動装置及びその制御方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3723840A (en) * 1972-01-21 1973-03-27 Power Control Corp Apparatus for motor current minimization
US3819992A (en) * 1972-01-21 1974-06-25 Power Control Corp Method and apparatus for providing efficient and stable power inversion with voltage and frequency control
US4291264A (en) * 1979-09-04 1981-09-22 Borg-Warner Corporation Power factor control system for inverter-driven a-c induction motor
US4420718A (en) * 1980-12-05 1983-12-13 Hitachi, Ltd. Control system for induction motor using inverter for AC power supply
US4546301A (en) * 1983-03-04 1985-10-08 Maschinenfabrik Stahlkontor Weserlenze GmbH & Co. Circuit and method for controlling an alternating or three-phase current motor
US4581568A (en) * 1982-12-11 1986-04-08 Fairford Electronics Ltd. Method and apparatus for automatically setting the demand phase lag input to an induction-motor power factor controller
US4590413A (en) * 1982-01-11 1986-05-20 Eaton Corporation EV drivetrain inverter with V/HZ optimization
US5010287A (en) * 1988-02-24 1991-04-23 Matsushita Electric Works, Ltd. Induction motor control system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59139893A (ja) * 1983-01-31 1984-08-10 Shinpo Kogyo Kk 誘導電動機制御装置
JPS59216493A (ja) * 1983-05-20 1984-12-06 Toshiba Corp 周波数変換装置
JP2712470B2 (ja) * 1989-01-23 1998-02-10 松下電器産業株式会社 インバータ装置の電流検出装置

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3723840A (en) * 1972-01-21 1973-03-27 Power Control Corp Apparatus for motor current minimization
US3819992A (en) * 1972-01-21 1974-06-25 Power Control Corp Method and apparatus for providing efficient and stable power inversion with voltage and frequency control
US4291264A (en) * 1979-09-04 1981-09-22 Borg-Warner Corporation Power factor control system for inverter-driven a-c induction motor
US4420718A (en) * 1980-12-05 1983-12-13 Hitachi, Ltd. Control system for induction motor using inverter for AC power supply
US4590413A (en) * 1982-01-11 1986-05-20 Eaton Corporation EV drivetrain inverter with V/HZ optimization
US4581568A (en) * 1982-12-11 1986-04-08 Fairford Electronics Ltd. Method and apparatus for automatically setting the demand phase lag input to an induction-motor power factor controller
US4546301A (en) * 1983-03-04 1985-10-08 Maschinenfabrik Stahlkontor Weserlenze GmbH & Co. Circuit and method for controlling an alternating or three-phase current motor
US5010287A (en) * 1988-02-24 1991-04-23 Matsushita Electric Works, Ltd. Induction motor control system

Cited By (64)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5686807A (en) * 1992-07-17 1997-11-11 Honda Giken Kogyo Kabushiki Kaisha Torque control system for AC motor
US5475292A (en) * 1992-07-28 1995-12-12 Fuji Electric Co., Ltd. Apparatus for restarting inverter for driving synchronous motor after momentary interruption
US5828192A (en) * 1993-02-02 1998-10-27 Honda Giken Kogyo Kabushiki Kaisha Electric vehicle power feed system
US5764022A (en) * 1993-12-28 1998-06-09 Sanyo Electric Co., Ltd. Air conditioner and inverter driving circuit therefor
US5724477A (en) * 1995-04-20 1998-03-03 Switched Reluctance Drives, Ltd. Compensation for input voltage variation in an electric motor drive
US5670859A (en) * 1995-06-23 1997-09-23 General Resource Corporation Feedback control of an inverter output bridge and motor system
EP1528660A1 (en) * 1995-12-28 2005-05-04 Kabushiki Kaisha Toshiba Three-phase bridge rectifier
US5808880A (en) * 1996-08-30 1998-09-15 Otis Elevator Company Power factor controller for active converter
US6832127B1 (en) * 1998-09-18 2004-12-14 Kabushiki Kaisha Yaskawa Denki Motor controller
US6442979B1 (en) * 1999-05-06 2002-09-03 Emerson Electric Co. Washing machine motor control device and method
US6400107B1 (en) * 1999-08-04 2002-06-04 Sharp Kabushiki Kaisha Motor control device capable of driving a synchronous motor with high efficiency and high reliability
US6366049B1 (en) * 2000-05-10 2002-04-02 Ecostar Electric Drive Systems L.L.C. Motor starter and speed controller system
US6531842B2 (en) 2001-06-25 2003-03-11 Schlumberger Technology Corp. Sine wave variable speed drive
EP1280264A2 (en) * 2001-07-27 2003-01-29 Hitachi, Ltd. AC current detecting device for inverter apparatus and AC current detecting method therefor
EP1280264A3 (en) * 2001-07-27 2003-08-06 Hitachi, Ltd. AC current detecting device for inverter apparatus and AC current detecting method therefor
US6693404B2 (en) * 2001-07-27 2004-02-17 Hitachi, Ltd. AC current detecting device for inverter apparatus and AC current detecting method therefor
US20080180056A1 (en) * 2001-09-29 2008-07-31 Toshiyuki Maeda Phase current detection method, inverter control method, motor control method and apparatus for carrying out these methods
US7671557B2 (en) * 2001-09-29 2010-03-02 Daikin Industries, Ltd. Phase current detection method, inverter control method, motor control method and apparatus for carrying out these methods
US6924618B2 (en) * 2003-03-25 2005-08-02 Matsushita Electric Industrial Co., Ltd. Inverter controller for driving motor, and air conditioner
US20040207360A1 (en) * 2003-03-25 2004-10-21 Hideo Matsushiro Inverter controller for driving motor, and air conditioner
US6972541B2 (en) * 2003-03-27 2005-12-06 Matsushita Electric Industrial Co., Ltd. Inverter control device for driving a motor and an air conditioner
US20040232876A1 (en) * 2003-03-27 2004-11-25 Hideo Matsushiro Inverter control device for driving a motor and an air conditioner
US7095208B2 (en) * 2003-04-03 2006-08-22 Matsushita Electric Industrial Co., Ltd. Inverter controller for driving motor and air conditioner using inverter controller
US20040217728A1 (en) * 2003-04-03 2004-11-04 Mitsuo Kawaji Inverter controller for driving motor and air conditioner using inverter controller
US20070278983A1 (en) * 2004-02-05 2007-12-06 Dyson Technology Limited Control of Electrical Machines
US20070252551A1 (en) * 2004-02-05 2007-11-01 Dyson Technology Limited Control of Electrical Machines
US7750594B2 (en) 2004-02-05 2010-07-06 Dyson Technology Limited Control of electrical machines
US7701164B2 (en) * 2004-02-05 2010-04-20 Dyson Technology Limited Control of electrical machines
US20060071629A1 (en) * 2004-07-07 2006-04-06 Rt Patent Company, Inc. Motor Controller
US7026785B1 (en) 2004-07-07 2006-04-11 Rt Patent Company, Inc. Motor controller
WO2006017026A1 (en) * 2004-07-07 2006-02-16 Raser Technologies, Inc. Motor controller
US20060038530A1 (en) * 2004-07-07 2006-02-23 Rt Patent Company, Inc. System and method for optimizing motor performance by varying flux
US7116029B2 (en) 2004-07-19 2006-10-03 Rt Patent Company, Inc. AC induction motor having multiple poles and increased stator/rotor gap
US20060012259A1 (en) * 2004-07-19 2006-01-19 Raser Technologies, Inc. AC induction motor having multiple poles and increased stator/rotor gap
US20060208603A1 (en) * 2005-03-18 2006-09-21 Rt Patent Company, Inc. Rotating electric machine with variable length air gap
US20070007929A1 (en) * 2005-07-07 2007-01-11 Kevin Lee System and method of controlling power to a non-motor load
US7932693B2 (en) * 2005-07-07 2011-04-26 Eaton Corporation System and method of controlling power to a non-motor load
US20070132331A1 (en) * 2005-12-13 2007-06-14 Rt Patent Company, Inc. DC homopolar motor/generator
US20070132334A1 (en) * 2005-12-14 2007-06-14 Rt Patent Company, Inc. Systems and methods for providing electrical contact with a rotating element of a machine
AU2008227057B2 (en) * 2007-09-28 2011-12-22 Rockwell Automation Technologies, Inc. Motor drive using flux adjustment to control power factor
US20090085510A1 (en) * 2007-09-28 2009-04-02 Manish Pande Motor Drive Using Flux Adjustment to Control Power Factor
US7683568B2 (en) * 2007-09-28 2010-03-23 Rockwell Automation Technologies, Inc. Motor drive using flux adjustment to control power factor
EP2043241A3 (en) * 2007-09-28 2014-12-03 Rockwell Automation Technologies, Inc. Motor Drive Using Flux Adjustment to Control Power Factor
CN101436773B (zh) * 2007-11-15 2012-10-03 上海华建电力设备股份有限公司 一种电动机再起动的方法
US7893650B2 (en) * 2008-01-29 2011-02-22 Azure Dynamics, Inc. Method and system for multiphase current sensing
US20090189553A1 (en) * 2008-01-29 2009-07-30 Arnet Beat J Method and system for multiphase current sensing
USRE45880E1 (en) * 2008-01-29 2016-02-02 Ge Hybrid Technologies, Llc Method and system for multiphase current sensing
US9179504B2 (en) * 2009-08-04 2015-11-03 Panasonic Intellectual Property Management Co., Ltd. Electric power converting apparatus and induction heating apparatus
US20140232308A1 (en) * 2011-10-04 2014-08-21 Mitsubishi Heavy Industries Automotive Thermal Systems Co., Ltd. Inverter apparatus
US9520824B2 (en) * 2011-10-04 2016-12-13 Mitsubishi Heavy Industries Automotive Thermal Systems Co., Ltd. Inverter apparatus
EP2582033A3 (en) * 2011-10-11 2014-04-23 Hamilton Sundstrand Corporation Control for a multi-level active rectifier
US20160020720A1 (en) * 2014-07-15 2016-01-21 IPH + Limited Drive control system and drive control method
US20160020716A1 (en) * 2014-07-15 2016-01-21 Nidec Motor Corporation Motor control system and method for input current protection
US9800139B2 (en) * 2014-07-15 2017-10-24 Nidec Motor Corporation Motor control system and method for input current protection
JP2016134959A (ja) * 2015-01-16 2016-07-25 株式会社デンソー モータ始動装置、モータ始動方法
US9707825B2 (en) * 2015-03-26 2017-07-18 Kabushiki Kaisha Toyota Jidoshokki Controller and in-vehicle motor-driven compressor
US20160285396A1 (en) * 2015-03-26 2016-09-29 Kabushiki Kaisha Toyota Jidoshokki Controller and in-vehicle motor-driven compressor
US20180191287A1 (en) * 2015-08-29 2018-07-05 Abb Schweiz Ag System having electrical machine and controller
US10630222B2 (en) * 2015-08-29 2020-04-21 Abb Schweiz Ag System having electrical machine and controller
US20170366101A1 (en) * 2016-06-17 2017-12-21 Denso Corporation Power conversion apparatus
US10116235B2 (en) * 2016-06-17 2018-10-30 Denso Corporation Power conversion apparatus
CN106411151A (zh) * 2016-08-29 2017-02-15 施电气科技（上海）有限公司 高效绝缘栅双极igbt结构变频器
US10277143B1 (en) * 2018-02-01 2019-04-30 Lsis Co., Ltd. Inverter supplying power to induction motor for driving hoist
US11394286B2 (en) * 2018-09-28 2022-07-19 Safran Power Usa, Llc Process control using amplitude control loop

Also Published As

Publication number Publication date
DE69023096D1 (de) 1995-11-23
EP0629038A2 (en) 1994-12-14
DE69023096T2 (de) 1996-05-09
EP0629038A3 (en) 1995-03-29
KR940006168B1 (ko) 1994-07-08
JPH03155392A (ja) 1991-07-03
DE69031573D1 (de) 1997-11-13
DE69031573T2 (de) 1998-02-19
EP0629038B1 (en) 1997-10-08
KR910010823A (ko) 1991-06-29

Similar Documents

Publication Publication Date Title
US5206575A (en) Device for controlling an AC motor
JP4988329B2 (ja) 永久磁石モータのビートレス制御装置
US20020149342A1 (en) Electric motor controller
JPS5850119B2 (ja) 無整流子電動機の制御装置
US7187155B2 (en) Leakage inductance saturation compensation for a slip control technique of a motor drive
JPH06343206A (ja) 電気自動車用の再構成可能な交流誘導モーター駆動システム
EP3570432B1 (en) Motor control device
JPH0548079B2 (ko)
JP2000232800A (ja) 永久磁石形同期電動機の制御装置
JPH07170799A (ja) 交流電動機の制御方法と装置および電動機電流の補正方法
EP0427571B1 (en) AC motor control
JPH1080180A (ja) 同期電動機の制御方法及び装置
Guziński et al. Sensorless Low Speed PMSM Motor Control with Cogging Torque Compensation
JPH05103498A (ja) 電動機制御装置
JP3489259B2 (ja) 永久磁石形電動機制御方法及び制御装置
JP3173022B2 (ja) ブラシレス直流モータの制御装置
JPH03253291A (ja) 電動機駆動装置
JP3124019B2 (ja) 誘導電動機の制御装置
JPH0458782A (ja) 交流電動機の駆動装置
JP2653873B2 (ja) インバータ電流制御装置
JP2677686B2 (ja) ブラシレスモータの駆動装置
JPS6330236Y2 (ko)
SU1259428A1 (ru) Вентильный электродвигатель
JPH0670571A (ja) インバータ装置の制御装置
JP2020178508A (ja) インバータ装置及びインバータ装置の制御方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: KABUSHIKI KAISHA TOSHIBA, 72, HORIKAWA-CHO, SAIWAI

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:NAKAMURA, YOSHINOBU;MOCHIKAWA, HIROSHI;REEL/FRAME:005575/0229

Effective date: 19901025

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 20010427

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362